STUDIES ON ANTIBACTERIAL ACTIVITY OF ACACIA NILOTICA

Abstract

This study was conducted as the first step to explore the possibility of isolating active ingredient(s) of Acacia nilotica as antibacterial agents. Two types of extracts from air-dried Acacia nilotica leaves were prepared through solvent extraction method using methanol and hexane. The disc diffusion method was used to screen 10 different pathogenic bacteria for their sensitivity to the leaf extracts. Acacia nilotica was found to be effective against Salmonella typhi, Shigella boydii, Shigella flexneri, Shigella sonnei, Vibrio cholerae 0139 and Hafnia. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of these extracts were determined. In case of methanol extract, the MIC values were 700mg ml^-1 against Salmonella typhi and 800 mg ml^-1  for each of Shigella boydii, and Shigella flexneri , whereas the corresponding MIC values for hexane extract were found 800, 800 and 900 mg ml^-1 respectively. The MBC values of methanol extract were found to be 800 mg ml^-1 for Salmonella typhi, 900 mg ml^-1 against each of Shigella boydii and Shigella flexneri and in case of hexane extract the MBC values were found 900, 1000 and 1200 mg ml^-1 respectively.